Distribute tests on release

[FRidh]

The repository includes tests but unfortunately these are not distributed on a release. Packagers are interested in these files because they're often used to test whether the packaged package actually works. On future releases please include the tests. Thanks!
(NixOS/nixpkgs#15751)

[msiemens]

PyGitUp v1.4.1 has just been released and includes the tests now :)

[FRidh]

Thanks!